Travis Rieder, Toward a Small Family Ethic: How Overpopulation and Climate Change Are Affecting the Morality of Procreation. Springer, 2016.

The global human population is currently about 7.6 billion people, and our numbers are still increasing. Although human population growth has not been a popular topic to discuss in the last quarter-century, its contribution to various environmental problems is becoming harder and harder to ignore. Travis Rieder’s Toward a Small Family Ethic confronts the effects of population growth and addresses what individual procreative obligations might follow from it.

This short book consists of five chapters. Rieder begins with a description of the population problem. More people need more land, more food, more fresh water, and more energy consumption to survive. Thus, a growing population puts greater strain on the environment that provides these vital resources. Rieder places a particularly strong emphasis on climate change and the ways in which mitigating climate change is made more difficult by the annual increases in emissions that result from population growth. Thus, the first chapter carries two important lessons: “population is a major driver of climate change, in addition to raising concerns about other limited resources” and “climate change is a morally urgent problem” (9).

With the nature of the problem established, Rieder turns to the main question of the book: in light of the impacts of human population growth, what obligations do individuals have with respect to their procreative decision-making? More specifically, might there be an obligation to limit one’s number of biological children? Ultimately, while Rieder does not affirm the existence of obligations to limit one’s biological procreation, he does conclude that “something disconcertingly close to this suggestion is true” (10). Or at least, he believes so with respect to wealthy individuals with large per capita ecological footprints.

In chapter 2, Rieder focuses on one of the strongest objections to the existence of duties to limit our procreation in response to the effects of population growth – the claim that one additional child makes such a small contribution to the large-scale environmental impacts under discussion that it really doesn’t make a significant difference in the grand scheme of things. Such reasoning reflects a moral principle akin to the following: “If the consequences of an act make no significant difference to the extent or severity of a moral problem, then the agent is not morally required to refrain from acting in light of the moral problem” (16). Consequentialists – those who regard the morality of an action as being determined exclusively by its consequences – are likely to find this line of reasoning persuasive. But Rieder believes such reasoning is misguided because there can be non-consequentialist reasons to refrain from certain activities even when one’s individual contribution makes a negligible difference to the overall effects of those activities.

In chapter 3, Rieder examines three non-consequentialist principles that could generate obligations to limit one’s procreation even if we grant that individual acts of procreation do not make a significant contribution to climate change and other environmental problems. The first is a duty not to contribute to massive systematic harms. Climate change, on Rieder’s assessment, is one of these harms, and along classic deontological lines, it can be considered objectionable to contribute to it regardless of how small one’s contributions are. The second is a principle of fairness. Overpopulation disproportionately harms the poor, and yet the wealthy, due to their carbon-intensive lifestyles, are the ones who contribute most to the problem. Such an arrangement is deeply unfair and violates the basic demands of social justice. The third is a duty to protect the interests of our possible children. Perils of the future – both environmental and otherwise – could cause serious harm to our children, and we ought not to expose them to severe risk of harm.

The first two of these three principles are better supported than the duty to protect our children from serious harm. The duty not to contribute to systematic harms is consistent with why many would find it wrong to buy cotton produced via slave labor even if individual purchases of cotton made no difference to the slaves’ welfare or their overall numbers. Certain practices are so morally repugnant that we are obligated not to participate in them even when our non-participation does not make a difference to thwarting them. Moreover, the unfairness associated with having a large, carbon-expensive family will resonate strongly with those who are aware of the enormous ecological footprints tied to western lifestyles and fact that developed nations have historically contributed so much more to the climate change problem than the global poor.

The risks to future children, however, do not seem severe enough (at least at present) to carry much weight in these decisions. People in the developed world are still very well-positioned to protect their children from serious harm. Rieder acknowledges this point briefly (37-38), but I think he overestimates the risks that people born in the near future (at least in the developed world) will face. Those who are more pessimistic about the future might find the duty to protect our children to be more stringent.

So what do these three principles entail? Rieder states that it is “plausible” that the moral considerations surveyed “entail a duty for many of us to have at most two children” (37). With this established, Rieder then examines objections to procreative obligations in chapter 4. The first major objection is that a moral duty to limit procreation threatens our integrity by hindering our abilities to pursue procreative projects – a central part of most people’s life plans. This objection is rather strong if the duty on offer requires having no children (since it would eliminate the possibility of biological parenthood), but its persuasiveness is less clear with respect to, say, a duty to limit oneself to two biological children. The second objection is that people have a right to have as many children as they want. Although Rieder acknowledges that rights can have limitations, he concedes that people may indeed have a right to unlimited control of their family size (50).

Interestingly, although Rieder suggests we might have the right to have as many children as we like, he thinks individuals in wealthy countries who have large families may still be subject to moral criticism. In chapter 5, Rieder notes that judgments about what is morally permissible can be separated from judgments about praise, blame, and our moral character more generally. Drawing on considerations tied to virtue ethics and the balance of reasons, he argues that many individuals will not be justified in having large families. Some people may be justified in having more than one child, but “the burden is on them to make the case” that their behavior is morally justified (66).

Toward a Small Family Ethic covers a lot of terrain given its length, and its brevity and accessibility make it a suitable introduction to the issues under discussion. Nonetheless, a 70-page text will inevitably have to gloss over or omit some important material. I will highlight three places where additional content would have been helpful.

First, the book does not feature much discussion of the positive externalities tied to procreation. For instance, as Julian Simon (1993) noted, a higher population means that there are more people with ideas that might lend themselves to technological innovation. More people who are well-educated and well-intentioned could, to some degree, be a good thing with respect to tackling a massive problem like climate change. Many also believe that, other things equal, the world is a better place when there are more people on it who are living good lives. I do not think these considerations outweigh the moral considerations that Rieder highlights, but other readers may disagree.

Second, Rieder briefly alludes to an argument by John Nolt (2011) that the average American could be responsible for the severe suffering or death of 1-2 future people, which would be quite morally significant even if the individual’s relative contribution to climate change is small. This argument could provide a straightforward refutation of the claim that one’s contribution to climate change is not morally significant and would hold more sway with consequentialist readers than Rieder’s non-consequentialist arguments. Thus, it is unfortunate the argument is mentioned and dismissed only in a footnote.

Third, the discussion of offsetting (21-22) proceeds too quickly. Offsetting one’s emissions would be an obvious strategy for justifying the additional carbon footprint created by procreation. Rieder points out that some offsetting strategies effectively involve replacing long-term carbon sinks with short-term ones, which is not an optimal solution. However, since the costs of offsetting are not presently that onerous, a person could offset substantially more than what seems necessary to account for the possibility that some of the offsets turn out to be short-term. Additionally, some forms of offsetting do not have this feature. Certain offsetting schemes involve the creation of renewable energy (e.g., wind turbines), and while it might take a much larger financial contribution to ensure that one’s individual donations actually make a difference, such a strategy can be viable in some circumstances. For some individuals, it may also be possible to offset their own emissions by purchasing and installing solar panels on their own homes. Ultimately, Rieder needs to say more about why offsetting is not a permissible strategy for rendering one’s procreation justifiable.

Beyond these considerations, I also wonder whether Rieder is right to back away from the claim that we have concrete obligations to limit our procreation. Until the end of chapter 4, he appears on the path to endorsing the view that people living in nations with high per capita carbon footprints have a prima facie obligation to have two or fewer biological children. He shies away from this claim because he is unable (perhaps due to space) to examine how our right to procreate might be limited by the demands of others. Given the trajectory of the text up to this point, this concession is surprising. Rieder highlights in chapter 1 that climate change threatens many people’s most vital interests. The victims of climate change may have their rights to life, health, and the means of subsistence jeopardized. These rights seem much more fundamental than a wealthy person’s right to have an unlimited number of biological children, especially if adoption is a viable option for the family in question. Rieder (2016) has argued elsewhere that procreative acts only contribute to causing harm to future people, and so we cannot straightforwardly weigh the right to unlimited procreation against the harms future people will suffer. Yet when the most fundamental rights of future people are threatened in large part because of the collective exercise of a much less fundamental right, there is a plausible case to be made that the less important right should be curtailed. Thus, I am not sure Rieder needs to concede that the right to procreate carries so much moral weight, and I would have rather seen him explore this issue in depth instead of devoting chapter 5 to a discussion of other moral considerations.

Nevertheless, despite my critical remarks, this book remains essential reading for those working on moral issues tied to population growth. Toward a Small Family Ethic presents novel arguments on a vital and underexplored moral issue. Problems tied to population growth will only get worse as the 21st century progresses, so we are fortunate that philosophers like Rieder are getting us started in thinking about this subject.